Broccoli (Brassica oleracea var. italia) is a variant of cruciferous Brassica cabbage, which is originally from Italy. Broccoli is rich in bioactive substances and nutrients, which is known as the “vegetable crown”. The nutritional ingredient of broccoli is not only high in content, but also very comprehensive, which mainly includes proteins, carbohydrates, fats, minerals, vitamin C and carotene and so on. According to the analysis, every 100 g fresh broccoli bulb, contains 3.5 g-4.5 g protein, which is 3 times of that in cauliflower, 4 times of that in tomato. Patent ZL200910091131.4 discloses a broccoli leaf protein and its preparation method, wherein, a flocculated protein is obtained by flocculating broccoli juice by adding acid with heating or adding acid and flocculant, then broccoli leaf protein is obtained by drying the flocculated protein.
With the deepening of the research on nutrition and so on, the biological function of protein peptide has been paid more and more attention. Protein peptide is a kind of compound whose molecular structure is between amino acid and protein. It is the structure and function fragment of protein, and has dual function of regulating the physiological function of the body and providing nutrition for the body. Protein peptide has a variety of biological activities, such as: immune regulation, anti-thrombosis, antihypertensive, cholesterol-lowering, inhibition of bacteria and viruses, anti-cancer effect, anti-oxidation and scavenging free radicals, improving element absorption and mineral transportation, promoting growth and so on. Modern nutrition research found that the protein absorbed by human body are mainly digested and absorbed in the form of oligopeptide after the proteins have been hydrolyzed by the enzyme in the digestive tract, the proportion of the proteins absorbed in the form of free amino acidis very small (Li Jianrong, Feng Ping. Progress in Study of Functional Polypeptides. Food Science, 2004, 25 (11): 415-419), so the polypeptide can be absorbed and used by the body more easily and faster than the protein and free amino acids, and the protein is absorbed in the form of a polypeptide, and it is also beneficial to maximize the use of its biological active function. Mature protein peptide products in foreign markets are corn protein peptide breakfast drinks from Japan, milk protein peptides anti-alcohol drinks from South Korea. In the market of China, the products are soybean protein peptide immunoregulation health care products, milk protein peptide nutritional supplements and so on.
In view of the high protein content of broccoli, the production of broccoli protein peptide using broccoli as a raw material can provide a new way for the high value-added utilization of broccoli. The invention selects different enzymes to hydrolyze broccoli protein, and screens out the broccoli protein peptide powder with high specificity, the powder has anti-oxidation and cholesterol-lowering and lipid-lowering activities; and can be used to develop health food with related functions. In addition, the broccoli protein peptide that we developed can also be developed as protein supplements or can also be used as raw materials for the production of cosmetics, food additives, beverages and so on.